Telephone substation apparatus



Jan. 13, 194 2. 1 c. E. LOMAX 2,279,966

TELEPHONE SUBSTATION APPARATUS Filed April 1, 1939 v 1/ J Connec/or Sui/Cl;

0p era fors Pas/flan Se/ec/or Stu/70h Se/ecfor Sill/f C15 .Lme Sal/lei; 3 =95 w w- I L Q 3 i} Q kwg INVENTOR. Clarence E. Lomax Patented Jan. 13, 1942 g i TELEPHONE SUBSTATION APPARATUS 4 Clarence E. Lomax, Oak Park, Ill.,-assignor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application April 1, 1939, Serial No. 265,459

9 Claims. (01. 179-63) T i The present invention relates to telephone substation apparatus of the paystation type and, more particularly,'to improvements in automatic paystation apparatus of the character wherein a certain number of impulse digits may be transmitted from a paystation over its associated line without the deposit of a coin, thereby to permit certain specified calls to be made from the station, and the transmission of an unrestricted number of digits from the station is contingent upon the deposit of a coin.

When paystations of the general character briefly described above are incorporated in an automatic-telephone system, the system switching apparatus may be so arranged that certain calls originating at the paystation may be rapidly and successfully completed without charge. For example, the automatic switching apparatus may be so arranged that calls originating at the paystations and intended for information operators fire stations, and police stations may successfully be completed without coin deposits. This may be accomplished by arranging the switching apparatus so that directory numbers of only a few digits are assigned to the particular telephone stations which are to be reached without coin deposits at the paystations. As to all other substations of the system, the switching apparatus may be so arranged that several additional digits are required to complete connections thereto. Various paystation arrangements permitting this type of service have been previously developed, all of which are rather complicated in character and are restricted'as to the coin collect and coin refund operations performed incident to the use of the apparatus in setting up regular substation connections.

It is an object of the present invention to provide improved-substation apparatus of the character briefly described which is of simple and I economical arrangement, is positive and reliable in its operation and is exceedingly simple to operate. 7

It is another object of the invention to provide improved substation apparatus of the character described wherein the coin collect and coin refund operations are automatically accomplished in a simple manner.

It is a further object of the invention to provide apparatus of the character described which is so arranged that fraudulent use of the apparatus is positively prevented.

In the illustrated embodiment of the invention, the usual means for receiving coins or the like and comprising a coin deposit channel, a coin collect channel and a coin refund channel is provided, together with an impulsing or calling device and a hook or cradle switch which is operative from a normal'position to an off-normal position to connect the impulsing device in a circuit including the line extending to the substation so that one or'more impulses may be transmitted over the line during each operation of the impulsing device. The apparatus further comprises means controlled by the impulsing device for preventing impulses from being transmitted over the line after a predetermined number of operations of the impulsing device.

Switching apparatus is also provided, operative in response to the deposit of a coin in the coin deposit channel of the coin receiving means, for rendering the above-mentioned impulse suppressing means ineffective to prevent the transmission of impulses over the line. In order automatically to obtain coin collection when a call routed from the station over the line is answered at the called station, there is provided a polarized electromagnetic device which includes a winding connected to be energized over a circuit, including the above-mentioned line, and operative only when current of a predetermined polarity traverses its winding; together with an armature controlled by the device for permitting a coin deposited and held in the deposit channel of the coin receiving means to pass into the coin collect channel. For the purpose of automatically refunding coins deposited during the initiation of calls. which are not completed, there is provided an element operative in response to operation of the hook or cradle switch from itsv off-normal position to its normal position to permit a coin deposited and held in the coin deposit channel of the coin receiving means to pass into the coin refund, channel. In order to prevent a user of theapparatus from fraudulently obtaining a refund of a deposited coin, there isalso provided a slow-acting device which functions to retard movement of the hook switch from its normal position to its off-normal; position. Thus, a user of the substation is prevented from obtaining a refund of a deposited coin without also releasing the switch train established incident to operation of the impulsing device. Further features of the invention pertain to the particular manner in which the elements described above are controlled and the manner in which the apparatus is completely restored to normal in response to operation of the hook or cradle switch from its elf-normal position to its normal position.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawing in which the single figure illustrates an automatic telephone system having incorporated therein substation apparatus constructed and arranged in accordance with the present invention.

Referring now to the drawing, the automatic telephone system there illustrated comprises a plurality of lines, three of which are indicated at (0, H, and I2 together with automatic switching apparatus for setting up connections between the lines. More particularly, the line I extends to an automatic substation A of the paystation type having incorporated therein the features of the invention as briefly outlined above, the line I I extends to an automatic substation B of conventional arrangement, and the line I2 is one of a group of lines extending to an operators position 13. This operators position may, for example, be one of the information operators telephone stations provided in the exchange housing the automatic switching apparatus. Alternatively, the equipment diagrammatically illustrated at 3, may represent a private branch exchange of the character conventionally provided in police or fire headquarters. The automatic switching equipment for setting up connections between the various lines of the system comprises the usual line switches, one of which is indicated at M, individually associated with the various lines emanating from the exchange; a plurality of first selector switches one of which is indicated at 5; a plurality of second selector switches one of which is indicated at It; and a plurality of connector switches one of which is indicated at I! as having access to the subscribers line H. Preferably, the line switches corresponding to and including the switch M, are of the wellknown non-homing rotary type, while the first selector, second selector and connector switches are of the well-known Strowger type of which several commercial embodiments are available. Each of the selector and connector switches is arranged to be seized over a trunk line extending thereto, these trunk lines individually including a pair of talking or line conductors and a control or private conductor. In order more clearly to explain the operation of the apparatus provided at the substation A, a portion of the control equipment embodied in the connector switch I! is illustrated in detail. More particularly, this control equipment comprises a line relay Illil which operates in response to seizure of the switch I"! and functions to repeat received impulses transmitted to this switch to the vertical and rotary magnets, not shown, conventionally provided in the switch. The indicated control equipment further comprises a battery reversing relay H0, which functions to reverse the direction of direct current flow over an established loop circuit extending to a calling substation when a call routed by way of the connector switch I! is answered at the called substation. In this regard it is pointed out that the calling and called loop circuits, both extending to the connector switch I! when a connection routed by way of this switch is completed, are separated by a conventional capacitance bridge comprising the condensers Hll and H32.

From the foregoing description relative to the arrangement of the switching equipment embodied in the system, it will be apparent that in order to establish a connection with one of the r lines extending to the operators position I3, a

two-digit number, such for example, as the number 00, must be dialed at the substation at which the call originates. On the other hand, in order to route a connection from a calling substation through one of the connector switches of the system to one of the subscribers lines, a fourdigit number, such for example, as the number 1582, must be dialed at the calling substation. By virtue of this arrangement of the lines, it is 5 possible, with the paystations of the system arranged in the manner hereinafter explained with referenc to the substation A, to initiate calls at these paystations without coin deposits. Calls to be routed to the regular subscribers lines and originating at the paystations can, however, only be completed after the paystation user makes the appropriate coin deposit.

Referring now more particularly to the substation A, the apparatus provided at this substation comprises a transmitter 20; a receiver 2|;

a dial operated impulsing device 22 including a shaft 35, pulsing springs 22a and shunt springs 22b; and a hook switch comprising a fixed contact 23 and a switchhook 24, this switchhook being operative from its normal position, as inline.

dicated in the drawing, to its off-normal position to engage the contact 23 and thus complete a loop circuit which extends by way of the line it to the line switch 14 associated with this There is also provided a signal device in the form of a bell 8 which is bridged across the conductors of th line H1 in series with a condenser 9. The apparatus further comprises coin receiving means which includes a coin deposit channel or chute 25 diverging into a coin collect channel or chute 26, and a coin refund channel or chute 21. For the purpose of selectively routing coins deposited in the coin deposit channel 25 into either of the coil collect and lift-refund channels 25 and 21, respectively, there are provided two spring biased rocker arms 28 and 29 individually including fingers arranged to block the passage of a coin deposited in the channel 25 into the channels 26 and 21, respec- "tively. The arm 28 is pivotally mounted at 28a to pass into the coin collect channel by means of a polarized electromagnetic device 3| of the permanent magnet type which includes a winding serially connected in one ,side of the line Hi. This winding is bypassed for voice frequency 6 currents through the provision of a capacitor 33 T position by means of a spring 32.

connected in shunt therewith. The other rocker arm 29, is pivotally mounted at 29a in any suitable manner and is biased to the coin blocking This arm is arranged to be rocked to a position which will vcoin in the coin deposit chute 25.

permit the passage of a coin from the channel 25 into the coin refund channel 21 in response to operation of a link or plunger 33 which is con trolled by operation of the switchhook 24.

As indicated above, the apparatus provided at the substation A is so arranged that only a predetermined number of impulse digits may be transmitted therefrom without the deposit of a To this end a cam 34 is mounted upon the main shaft 35 of the impulsing device 22 and is arranged to drive stepby-step, at the rate of one step for each operation of the impulsing device 22, a ratchet wheel 35 which functions to control a circuit for effectively short circuiting the pulsing springs 22a of the impulsing device 22. More particularly, the ratchet wheel 36 is rotatably mounted upon a shaft 31 and carries a cam projection 39 which, in the normal position of the ratchet wheel is biased to engage a stop 31a under the influence of a coil spring 38. The cam projection 39 is adapted to engage a cam follower 40 when the ratchet wheel 36 is operated from its normal position to a predetermined off-normal position. The cam follower 40 is arranged directly to control a movable contact spring 4| which is commonly included in a path normally short circuiting the winding of the electromagnetic device 3| and the above-mentioned circuit for short circuiting the pulsing springs 22a of the impulsing device 22. In order to drive the ratchet wheel 35 in response to operation of the shaft 35 there is provided a ratchet and pawl mechanism which comprises a rocker arm 42 pivotally mounted at 43 and carrying at its free end a pawl 44 which is spring biased by means of a spring 45 into engagement with a stop 46. The rocker arm 42 has fixedly mounted thereon a cam follower 41 which is biased into engagement with the peripheral surface of the cam 34 by means of a spring 48.

For the purpose of retaining the ratchet wheel 36 in its operated position following each step taken thereby, there is provided a retaining pawl 49 which is pivotally mounted at 50 and is biased to engage the teeth of the ratchet wheel 36 by means of a spring This retaining pawl is normally retracted out of engagement with the teeth of the ratchet wheel 36 by providing an extension 24a of the switchhook 24; this extension being arranged to rock the retaining pawl 49 away from the teeth of the ratchet wheel 36 when the switch hook 24 is operated from its oil-normal position to its normal position in response to replacement of the receiver 2| upon the switchhook 24.

In order to render the apparatus described in the preceding paragraph inefiective to prevent the transmission of impulses from the substation A when a coin is deposited inthe coin deposit channel 25 of the coin receiving means, there is included in the above-mentioned circuit for short circuiting the springs 22a of the impulsing device 22, a cantilever mounted conductive spring 52 which normally engages an associated fixed contact 53 and is adapted to be moved out of engagement with the contact 52 in response to move ment of a rocker arm 54, resulting from the deposit of a coin in the coin deposit channel 25. More particularly, the arm 54 is pivotally mounted at 54a and includes a finger projecting in the path of a coin deposited in the channel 25, so that it is rocked in a counter-clockwise direction to move the spring 52 out of engagement with the fixed contact 53 each time a coin is deposited in the channel 25. In order to retain the spring 52 in its operated position following operation of the rocker arm 54, there is provided a latching spring 55 having one end fixedly mounted at 55a and carrying intermediate its two ends a latch 56 which is adapted to cooperate with the free end of the spring 52 to retain this spring 52 in its operated position. The free end of the latching spring 55 cooperateswithasecondextension 24b of the switchhook24inamanner suchthat the spring is operated from its latching position to a position out of engagement with the spring 52 in response to movement of the switch hook from its off-normal position to its normal position. In order to prevent the unauthorized refund of a coin deposited in the coin deposit channel. 25 of the coin receiving means in the manner more fully explained hereinafter, there is associated with the switchhook 24 a slow-actingdev'ice in the form of a dashpot 51 which retards movement of the switchhook from its normal position to its oil-normal position.

Referring now more particularly to the operation of the apparatus, in order to initiate a call at'the substation A, the receiver 2| is first removed from its supporting hook 24 permitting this hook to be rotated clockwise into engagement with the fixed contact 23 under the infiuence of the biasing springs 5| and 32. During.

such rotary movement of the switchhook 24, the

extension 24a is moved downward permitting the retaining pawl 49 to be rotated clockwise under channel 21. When the switchhook 24 engages its associated fixed contact 23, a loop circuit is completed from the substation A to the line'switch M. This loop circuit may be. partially traced as extending by way of the line conductor Illa, the switchhook'24, the contact 23, the transmitter 20, the receiver 2 I, the pulsing springs 22, the movable contact spring 4| and its associated fixed contact 4| a, and the opposite line conductor Iflb. When this loop circuit is completed, the line switch I4 operates in the usual manner to select an idle one of the first selector switches to which it has access and to mark the calling line I!) as busy in the bank contacts of the connector switches having access thereto. If it be assumed, for example, that the first selector switch I5 is the first available idle one of the switches accessible to the line switch l4, when the last-mentioned switch functions to test the condition of the trunk line extending to the switch I5 and finds the trunk line to be idle, it operates to switch the calling loop circuit through to this selector switch. The selector switch l5, in turn, responds to the extension of the calling loop circuit thereto by operating to condition itself to respond to the impulses of the first digit dialed.

at the callingsubstation A. The next operation performed by the calling party depends upon the character of the call. Thus, if the call is to be forwarded to a telephone station, such, for example, as that provided at the operators position l3, terminating a line accessible to certain of the second selector switches, the calling party first, that the call initiated at the substation A is to be forwarded to the operators position |3,.th'e

calling party proceeds to goperatethe impulsing device 22 in accordance withthe .direct ory number designating the operators position.

During each operation of the calling device 22, the shunt springs 221) are closed to complete an obvious path for short circuiting the series connected transmitter 20 and receiver 2|, thus lowering the resistance of the loop circuit over which the impulses are transmitted to the automatic switching apparatus. Also, during each operation of the impulsing device 22, the cam 34carried by the shaft 35 is rotated from its normal position, as shown in the drawing, to an off-normal position determined by the number of the digit dialed. This camis rotated in a clockwise direction during the forward movement of the dial and, during such rotation, the cam follower 41' is raised to rotate the aim 42in a clockwise direction thus causing the pawl 44 carried by this arm to engage one of the'teeth of the ratchet Wheel 36 and to rotate this ratchet wheel one step. During such rotation of the ratchet wheel, the retaining pawl 55 rides over the tooth of the ratchet wheel 36 which it engages and drops into engagement with the next succeeding tooth, thereby. to retain the ratchet wheel in its operated position. During the return movement of the dial, the cam 34 is rotated back to its normal position, permitting the cam follower ll to drop into the notch formed in the periphery of the cam 34 so that the arm 42 is returned to its normal position under the influence of the spring 48, thereby to condition the pawl mechanism to operate the ratchet wheel 36 a second step. Also, when the shaft 35 assumes its normal position at the end of the return movement of the dial, the shunt springs 2% are opened to interrupt the above-mentioned path for short circuiting the receiver 2| and the transmitter 2B. The cycle of operations just described are repeated during each operation of the impulsing device 22. Thus, the ratchet wheel 36 is advanced one step in response to each operation of the impulsing device. Since the pulsing springs 22a of the impulsing device 22 are opened and closed one or more times during each operation of this device, current impulses are transmitted in the usual manner over the line to the automatic switching apparatus terminating this line.

The selector switch responds to the impulses of the first digit dialed by operating in a conventional manner to elevate its wipers opposite the level of bank contacts terminating the desired group of trunk lines. During the inter-digit pause between the first and second digits, this selector switch functions, also in a conventional manner, automatically to select a trunk line extending to an idle one of the second selector switches in the selected group, and to switch the calling loop circuit through to the selected second selector switch. Assuming, for example, that the second selector switch I 6 is seized by the first selector switch l5, when the calling loop circuit is switched through to the switch IS, the switch is automatically conditioned to respond to the impulses of the second digit dialed at the calling substation A. The second selector switch l6 responds to the impulses of the second digit by operating to select a desired group of lines and thereafter to select an idle one of the selected group of lines in the exact manner just described with reference to the first selector switch 15. In the present case, the two digits dialed at the calling substation A will cause the connection to be routed through the selector switches 15 and H3 to the group of lines including the line l2. Assuming that the line i2 is the firstavailable idle line of this group, the selector switch 16 operates to seize this line and to switch the calling loop circuit through to the operators position l3. In response to thelast-mentioned operation, the trunk circuit apparatus terminating the line l2 at the operators position l3 functions'to impress ground potential upon the control or private conductor of the line l2, thereby to maintain the selector switches l5 and I6 operated in the usual manner and, also, to energize the signal device provided at the operators position 13, thereby to indicate that an incoming call is present upon the line 12. When the operator answers the call, the desired conversational circuit is fully completed and the calling party may converse with the operator to obtain the service or information desired.

The release of the established connection is primarily under the control of the operator who answers the call at the operators position I3. More particularly, when the calling party at the substation A replaces the receiver 2| upon the switchhook 24 at the end of the conversation, the calling loop circuit is interrupted and the operator attending the position l3 receives the usual disconnect signal and proceeds to clear out the connection. During the release of the trunk circuit apparatus terminating the line 12 at the operators position, ground potential is removed from the control conductor of the line l2 and the operated automatic switches l5 and I6 are released in the usual manner. When the receiver 2! is replaced upon the hook 24, the Weight of the receiver causes the switch-hook 24 to be rotated in a counter-clockwise direction back to its normal position. During such movement, the link 33 is moved downward under the influence of the switchhook 26 to rotate the rocker arm 29 in a clockwise direction against the bias of the spring 32, so that the finger portion thereof is moved out of the coin refund channel 21. In addition, the retaining pawl 49 is moved against the bias of the spring 5| in a counter-clockwise direction out of engagement with the teeth of the ratchet wheel .36 in response to the counterclockwise movement of the switchhook 24, thus permitting the ratchet wheel to be returned to its normal position under the influence of the spring 38. During movement of the switchhook to its normal position, the extension 2472 thereof is elevated to move the free end of the spring 55 so that the 1atch'56 carried thereby no longer engages the freeend of the contact spring 52. Thus, the apparatus provided at the substation A is fully restored to normal.

In the foregoing explanation with reference to the call routed to the operators position 13, the desired connection was successfully completed because the ratchet wheel .35 was not rotated a sufficient amount to afiect movement of the movable spring 4| into engagement with the contact M b. If, however, the calling party attempts to dial more than two digits without depositing a coin in the coin deposit channel 25 of the coin receiving means, the ratchet wheel 36 is rotated a suilicient amount, upon the third operation of the impulsing device 22, to bring the cam projection 39 into engagement with the cam follower 40 so that the movable contact spring 4| is moved out of engagement with its associated contact Ma and into engagement with its associated contact Mb. As a result, the path normally short-circuiting the winding of the electromagnetic device 3| isinterrupted, thereby serially to include this winding in the calling loop circuit, and the pulsing springs 22a are effectively excluded from the loop circuit extending to the automatic switching equipment; thus preventing further impulses from being transmitted from the substation A over the line H) to the automatic switching apparatus. The direction of current flow over the calling loop circuit is such that the polarized electromagnetic device 3| does not operate at this time. More specifically, en-

, gagement of the contact spring 4| with the contact Mb, eifects the closure of the previously mentioned path for effectively short-circuiting the pulsing springs 22a. This path may be traced as extending from the line conductor Illa by Way of the contact53, the spring 52, the contact 4|b and the contact spring 4| to the opposite line conductor IUb. As a consequence of the complethe connector switch IT to cause the wipers of tion of this path, a connection cannot be extended beyond the second selector switch I6 regardless of the number of operations of the impulsing device 22. It will be apparent, therefore, that a calling party at the substation A is positively prevented from obtaining connections to the regular substations of the system without first depositing a coin in the coin receiving means.

During ordinary use of the substation A, wherein the calling party first removes the receiver 2| from the switchhook 24, then inserts a coin in the coin deposit channel 25 of the coin receiving means and thereafter dials the digits of the directory number designating the desired substation, the above-traced circuit for shortcircuiting the pulsing springs 22a of the impulsing device 22 is not completed. More particularly, when a coin is deposited in the coin duct 25 following operation of the switchhook 24 to its off-normal position, the rocker arm 54 is rotated in a counter-clockwise direction to move the free end of the spring 52 to the right a sufficient amount so that the latching element 55 is moved downward under the influence of the spring 55 to latch the spring 52 in-a position out of engagement with the contact 53. Hence, when thereafter and during the dialing operation, the movable contact spring 4| is moved out of engagement with its associated spring Ma and into engagement with its associated spring MD, the previously traced path short-circuiting the pulsing springs 22a is not completed. It is noted, however, that this operation on the part of the movable spring 4| interrupts the path normally short-circuiting the operating winding of the electromagnetic device 3|, thereby serially to include this winding in the established loop circuit extending to the automatic switching apparatus. It is noted further that with the switchhook 24 occupying its off-normal position, the rocker arm 29 is moved to its coin blocking position so that the deposited coin is held in the duct 25 between the coin retaining fingers of the two arms, 28 and 29.

If it be assumed, for example, thatthe call under consideration is to be routed to the substation B associated with the line H and, further, that the connector switch I1 is seized by the selector switch I6 at the end of the second digit dialed at the substation A, the indicated selector switch |6 operates to switch the calling loop circuit through to the connector switch whereby the line relay I00 of this connector switch is energized and operates. The manner in which the line relay I05 functions to repeat the impulses of the third and fourth digits dialed at the substation A to the vertical and rotary magnets of this switch to be positioned in engagement with the contacts terminating the conductors of the desired line H, is entirely conventional. Following the selection of the called line I I, this line is tested in the usual manner to determine the idle or busy condition thereof and if found busy, the usual busy tone signal is returned to the calling party. On the other hand, if the called line is idle, the control apparatus of the connector switch functions in a well-known manner to project ringing current thereover and to return the usual ring back tone signal to the calling party. When the call is answered at the called substation, a direct current bridge is placed across the line conductors of the line H and a loop circuit is completed for energizing the called party answer or battery reversing relay H0. When energized over this loop circuit, the relay operates its armatures to H4, inclusive, to reverse the direction of current flow over the loop circuit extending to the calling substation A. Following operation of the relay I H], the direction of current flow through the operating winding of the polarized electromagnetic device 3| is such that the electromagnetic device 3| operates to attract the rocker arm 28 thereby to move the coin blocking finger of this arm to a position such that the coin held in the duct 25 is permitted to pass through the coin collect channel 26 to a coin receiving box. Simultaneous With the last-mentioned operation, the desired conversational circuit between the calling and called substations is completed. At the end of the conversation and when the connection is cleared out at the called substation B, the connector switch I! is released and the battery reversing relay I ll] restores to again reverse the direction of current flow over the calling loop circuit with the result that the electromagnetic device 3| is released to permit the rocker arm 28 to be restored to its normal position under the influence of the spring 30. The remaining steps in the release of the apparatus are exactly the same as set forth previously with reference to the call routed to the operators position l3.

In the event the called line H is busy at the time it is selected by the connector switch H, or the calling party at the substation A abandons the call before it is answered, the polarized electromagnetic dvice 3| is not caused to operate and the deposited coin held in the coin deposit duct 25 is returned to the calling party when the receiver 2| is replaced upon the switchhook 24. More particularly, when the switchhook 24 is returned to its normal position, the link 33 is moved downward to rotate the rocker arm 29 in a clockwise direction so that the coin blocking finger thereof is moved out of the coin refund channel 2''! to permit the deposited coin to pass through this channel to the coin refund pocket conventionally provided in substations of the pay station type.

From the preceding explanation it will be understood that the calling party might, by momentarily depressing the switchhook 24, obtain the refund of the deposited coin. It will also be apparent that if the switchhookwere operated from its elf-normal position to its normal position and back to its off-normal position with sufficient rapidity, a refund of the deposited coin might be obtained without releasing the operated switch train through which the connection is routed to the called substation. In order to obviate this difliculty, the slow-acting device or dashpot 51 is provided, this device functioning to retard movement of the switchhoolz- 24 from its normal to its ofi-normal position. Thus, when the switchhook is depressed from its off-normal position to its normal position and then released, the device 5'! retards the movement of the switch hook suffioiently so that the calling loop circuit is maintained interrupted at the contact 23 for a time interval greater than the interval required for the release of the operated switch train. By virtue of this arrangement, a user of the apparatus provided atthe substation A is precluded from obtaining a connection and thereafter fraudulently obtaining a refund of the deposited coin.

On a call incoming to the substation A, the signal device 8 is energized by ringing current projected over the line It! shortly following seizure of this line by the operated connector switch through which the call is routed. To answer the call, the receiver 2! is removed from its supporting hook 24 to establish the previously traced direct current bridge across the conductors of the line Hi. When this bridging path is completed the connector switch, through which the connection extends, operates to terminate the ringing operation and to establish the desired talking circuit in the usual manner. In this case the partial operation of the coin collecting and call restricting apparatus is without effect,

all of the elements of this apparatus being fully restored to normal in an obvious manner when the receiver 2| is replaced upon the switchhook 24 at the end of the conversation.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood that various modificationsmay be made therein, and it is contemplated to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is: l

1. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and including a coin deposit channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line to transmit one or more impulses over said line during each operation of said device, means controlled by said impulsing device for preventing impulses from being transmitted from said substation over, said line after a predetermined number of operations of said device, means responsive to the deposit of a coin in said coin deposit channel for rendering said last-named means inefiective to prevent the transmission of impulses over said line, a polarized electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit channel to pass into said coin collect channel, a path normally short-circuiting said winding, and

means operative after said predetermined number of operations of said impulsing device for interrupting said path.

2. A telephone substation adapted to be con nected to a telephone line and comprising, in combination, means for receiving coins or the like and including a coin deposit channel and a coin collect channel, an impulsing device adapted to be connected in a' circuit including said line and operative-to transmit one ormore impulses: over said line during each operation thereof, anelement operative to a predetermined position in response to a predetermined number of operations ofsaid device, a circuit completed in response to operation of said element tosaid predetermined position to prevent impulses-from beingtransmitted from said substation over said line, aswitch operative to interrupt said circuit inresponse to the deposit of a coin in said coin deposit channel, a polarized electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit channel to pass into said coin collectchannel. a path normally short-circuiting said winding, and means responsive to-operation of said element to said predetermined position for interrupting said path.

3. A telephone substation adapted to be connected to atelephon'e line and comprising, in combination, means for receiving coins or the like and including a coin deposit channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one-or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to'an off-normal position tocomplete said circuit, an element having a normal position and operative to a predetermined offnormal position in response to a predetermined number of operations ofsaid impulsing device, means responsive to operation of said element to said predetermined ofi-normal position for preventing impulses from being transmitted from said substation oversaidline, means responsive to the deposit of a coin in said coin deposit channel for rendering said last-named means ineffective to prevent the transmission of impulses over said'line, a'polarized electromagnetic device including a winding connected to beenergized over a circuit including saidline and operative only when current of a predetermined polaritytraverses said winding, means controlled by'said electromagnetic devicefor permitting a coin deposited in' said deposit channel to pass into said coin collect channel, means operative to cause said element to be returned to its normal position in response to operation of said hook switch from its off-normal position to its normal position, andmeans comprising a slowacting device for retarding movement of said hook switch from its normal position to its oilnormal position,

4'. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and including a coin deposit channel and a coin collect channel, an impulsing deviceadapted to be connected in a circuit including said line and operativeto transmit one or more impulses over' said line during each operation thereof, a hook or cradle switch having a normal position and operative to an ofi-normal position to complete said circuit, anelement having a normal position and operative to a predetermined off-normal position in response to a pre determined number of operations of said impulsing device, a circuit completed in response to operation of said element to said predetermined off-normal position to prevent impulses from being transmitted from said substation over said line, a second switch having a normal position and operative to an off-normal position to interrupt said circuit in response to the deposit of a coin in said coin deposit channel, a polarized electromagnetic device including a winding connected. to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit. channel to pass into said coin collect channel, and means operative t cause said second switch to be returned to its normal position in response to operation of said hook switch from its off-normal position t its normal position.

5. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and. including a coin deposit channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to an off-normal position to complete said circuit, an element having a normal position and operative to a predetermined off-normal position in response to a predetermined number of operations of said impulsing device, a circuit completed in response to operation of said element to said predetermined off-normal position to prevent impulses from being transmitted from said substation over said line, a second switch having a normal position and. operative to an 01fnormal position to interrupt said circuit in response to the deposit of a coin in said coin deposit channel, a polarized electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit channel to pass into said coin collect channel, means operative to cause said second switch to be returned to its normal position in response to operation of said hook switch from its off-normal position to its normal position, and means operative to cause said element to be returned to its normal position in response to operation of said hook switch from its off-normal position to its normal position.

6. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and comprising a coin deposit channel, a coin refund channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to an off-normal position to complete said circuit, an element having a normal position and. operative to a predetermined off-normal position in response to a predetermined number of operations of said impulsing device, means responsive to operation of said element to said predetermined oif-normal position for preventing impulses from being transmitted from said substation over said line, means responsive to the deposit of a coin in said coin deposit channel for rendering said last-named means ineffective to prevent the transmission of impulses over said line, a polarized electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit channel to pass into said coin collect channel, means operative in response to operation of said hook switch from its off-normal position to its normal position for permitting a coin deposited in said coin deposit channel to pass into said coin refund channel, and means comprising a slowacting device for retarding movement of said hook switch from its normal position to its off-normal position.

'7. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and comprising a coin deposit channel, a coin refund channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to an offnormal position to complete said circuit, an element having a normal position and operative to a predetermined off-normal position in response to a predetermined number of operations of said impulsing device, means responsive to operation of said element to said predetermined off-normal position for preventing impulses from being transmitted from said substation over said line, means responsive to the deposit of a coin in said coin deposit channel for rendering said lastnamed means ineifective to prevent the transmission of impulses over said line, a polarized electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited in said deposit channel to pass into said coin collect channel, means operative in response to operation of said hook switch from its oil-normal position to its normal position for permitting a coin deposited in said coin deposit channel to pass into said coin refund channel, means operative to cause said element to be returned to its normal position in response to operation of said hook switch from its off-normal position to its normal position, and means comprising a slow-acting device for retarding movement of said hook switch from its normal position to its off-normal position.

8. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and comprising a coin deposit channel, a coin refund channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to an offnormal position to complete said circuit, an element having a normal position and operative to a predetermined off-normal position in response to a predetermined number of operations of said impulsing device, a circuit completed in response to operation of said element to said predetermined off-normal position to prevent impulses from being transmitted from said substation over said line, a second switch having a normal position and operative to an off-normal position to interrupt said circuit in response to the deposit of a coin in said coin deposit channel, a polarized electromagnetic device including a winding connected to. be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding, means controlled by said electromagnetic device for permitting a coin deposited and held in said coin deposit channel to pass into said coin collect channel, means operative in response to operation of said hook switch from its off-normal position to its normal position for permitting a coin deposited in said coin deposit channel to pass into said coin refund channel, and means operative to cause said second switch to be returned to its normal position in response to operation of said hook switch from its oiT-normal position to its normal position.

9. A telephone substation adapted to be connected to a telephone line and comprising, in combination, means for receiving coins or the like and comprising a coin deposit channel, a coin refund channel and a coin collect channel, an impulsing device adapted to be connected in a circuit including said line and operative to transmit one or more impulses over said line during each operation thereof, a hook or cradle switch having a normal position and operative to an ofinormal position to complete said circuit, an element having a normal position and operative to electromagnetic device including a winding connected to be energized over a circuit including said line and operative only when current of a predetermined polarity traverses said winding,

means controlled by said electromagnetic device for permitting a coin deposited in said coin deposit channel to pass into said coin collect channel, means operative in response to operation of said hook switch from its off-normal position to its normal position for permitting a coin deposited in said coin deposit channel to pass into said coin refund channel, means operative to cause said second switch to be returned to its normal position in response to operation of said hook switch from its oiT-normal position to its normal position, and means operative to cause said element to be returned to its normal position in response to operation of said hook switch from its off-normal position to its normal position.

CLARENCE E. LOMAX. 

